Research Project
9566332
Project Summary/Abstract Background: Prosthetic replacement of diseased and damaged joints is one of the great advances of modern medicine. Prosthetic joint infections (PJI) however are a serious complication. Improved operative techniques have reduced the risk of PJI soon after surgery but late PJI (LPJI) are an ongoing risk for the >7 million individuals with a prosthetic joint in the US. In an attempt to reduce this risk dentists are encouraged to give prosthetic joint patients antibiotics before invasive dental procedures (IDP) to reduce the risk of bacteria entering the circulation and infecting the joint. This is called antibiotic prophylaxis (AP). However, there has never been a trial to demonstrate AP efficacy and there is little evidence to support an association between IDP and LPJI. As a result, AP guidelines are confused and differ around the world. In the US, AP is widely used although the AP guidelines are unclear and baffling for both clinicians and their patients. In contrast, AP has never been used in the UK. To resolve this confusion and guide clinicians, data proving or disproving any association between IDP and LPJI is urgently needed. If an association exists, then the widespread adoption of AP could help reduce the ~20,000 cases and ~$566 million annual cost of LPJI in the US. If not, then AP is unnecessary and could be stopped saving ~$60 million annually, avoiding the risk of adverse reactions to AP antibiotics and the risk to society that AP may promote the development of antibiotic resistant bacteria. Objectives: To determine if IDP are causally associated with the development of LPJI or not. Specific Aims: (i) To perform a case-crossover study to determine if the frequency of IDP in the 3 months immediately preceding LPJI is significantly greater than in earlier 3 month matched control periods i.e. 3-6, 6-9 and 9-12 months before the LPJI. (ii) We will also perform a case control study comparing the incidence of dental treatment involving and not involving an IDP in the 3 months preceding an LPJI. Methods: We will use national Hospital Episode Statistics (HES) data to identify LPJI patients in England from 2010-2017. We will use English data because (i) AP, that could hide any association between IDP and LPJI, has never been used in England and (ii) the UK National Health Service (NHS) data systems allows us to link courses of dental treatment (CoT) to cases of LPJI. Using each LPJI patient?s NHS number we can link the LPJI data to each individual?s dental data. This will allow us to determine if patients who develop LPJI had a CoT in the preceding year, if it involved an IDP or not and when it occurred in relation to the hospital admission. We will use the powerful case-crossover analysis method to determine if the incidence of IDP in the 3 months preceding LPJI (case periods) was significantly higher, or not, than the incidence in each of the earlier 3 month periods (3-6, 6-9 and 9-12 months before LPJI). A more traditional case-control analysis will also be performed to see if CoT involving an IDP occurred significantly more frequently than CoT not involving an IDP in the 3 months preceding an IDP. These methods will provide the statistical power to determine if IDP are associated with LPJI or not.
